WeChat

Tencent’s mobile chat app has been accused by some of being a copycat (and those complaints are not without merit), but that hasn’t stopped WeChat from growing at breakneck pace. With 300-million-plus users, it’s far and away the mobile chat app of choice in China, but perhaps more importantly, it’s probably the first Chinese social network to see real success overseas, with more than 40 million international users as of April 2013.